Caliskan 2009.

Methods	RCT, single centre (Turkey).
Participants	Women from 34 weeks' gestation undergoing induction of labour with oral misoprostol. Inclusion: singleton live pregnancy with vertex presentation and maternal and/or fetal indications for induction of labour; gestational age from 34 weeks; Bishop score less than or equal to 5; absence of spontaneous uterine contractions; estimated fetal body weight less than 4250 g; reactive non‐stress test. Exclusion: fetal demise; gestational age less than 34 weeks; known hypersensitivity to prostaglandin; previous caesarean section or other uterine surgery; contraindication to vaginal birth.
Interventions	Group 1: electronic fetal monitoring by CTG only. If the CTG was reassuring, labour continued unless otherwise indicated. If the CTG was nonreassuring (defined), simple measures, including lateral positioning, were instigated, with escalation to operative birth if simple measures were not effective. Group 2: CTG plus FSpO2 monitoring ‐ intermittently for 15 minutes every 2 hours. If reassuring it was removed. If nonreassuring, remained in situ. If the CTG was reassuring and FSpO2 values were greater than or equal to 30%, labour continued unless otherwise indicated. If the CTG was nonreassuring (defined) and FSpO2 values were less than 30% for 3 minutes, simple measures, including lateral positioning, were instigated. If FSpO2 values remained < 30% for 10 minutes, then operative birth was performed.
Outcomes	Primary outcome: caesarean birth rates. Secondary outcomes: induction to birth interval, caesarean section for nonreassuring CTG, neonatal outcomes, including umbilical arterial pH < 7.16, admission to neonatal intensive care.
Notes	Fetal oximetry system used: Nellcor OxiFirst. 37 weeks used as 'restriction point' to randomly allocate preterm and term fetuses to the 2 groups. This is interpreted as stratification by term/preterm, however, no further details provided of outcomes within these groups. Data were not available to allow subgroup analysis in this review by term/preterm. Similar numbers of term (total n = 195)/preterm (total n = 35) were randomised to the control and intervention groups, with the larger proportion being term in each group. There were similar neonatal outcomes (including birthweight and admission to NICU), both between the groups and compared with other studies enrolling over 36 weeks. We have therefore included these participants in the analyses of later gestations, renaming the analyses that include participants from this study as "... gestation from 34 weeks ...". Attempts at establishing contact details to clarify this were unsuccessful.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐based randomisation reported to be "Directed by a physician".
Allocation concealment (selection bias)	Low risk	Sequentially numbered opaque envelopes.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants were unblinded. It would not have been feasible to blind the clinician or participant, given that FSpO2 values were used for clinical judgement.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	The authors did not state whether or not outcome assessment was blinded.
Incomplete outcome data (attrition bias) All outcomes	Low risk	A flowchart of the eligible and enrolled participants was included in the publication and outcomes were reported for all these participants.
Selective reporting (reporting bias)	Low risk	No evidence of selective reporting.
Other bias	Low risk	No evidence of other bias, although there is no evidence of trial registration or study protocol publication.